Tuesday, October 29, 2013

Reassembly begins with the crankshaft. I have completely stripped the crank, cleaned the sludge-tube (what acts as the oil filtration mechanism in these engines) and cleaned, measured and inspected the rod and main bearing journals and found them to be in excellent condition and standard size. Having done that, reassembly can now begin.

Here we have the crank and the parts related to the sludge-tube. They are the tube itself, the flywheel bolt that retains the tube and the new oil galley plug. Note the tape protecting the timing-side main bearing journal.

Note the small hole in the middle of the sludge-tube, the small projection on the end of the flywheel bolt engages that hole and retains the tube. The tube is a pretty snug press-fit into the crank and unless you want to remove it again, you need to make sure that the hole in the tube aligns with the hole in the crank when you insert the tube. Here's how I do it.
I machined an alignment pin to show when the holes in the crank and tube coincide.

I start the tube into the crank, drop the pin into the flywheel bolt hole and gently tap the tube in until the pin drops, signifying proper alignment.
Started:

Aligned:

The Flywheel bolt is red Loc-Tite coated and installed at 33 foot-pounds torque and the plug is blue Loc-Tite coated, tightened and staked in place.

Now we move on to installing the connecting rods.
Having installed new bearing shells and made sure that everything is scrupulously clean, the rod and cap are assembled to the (lightly oiled) journal and the rod bolts are measured before and after torquing to ascertain the amount of stretch (preload) in the rod bolt. They should measure .004"-.006" longer after torquing.

With the crank assembled we can move on to assembling the crankcase halves. First the crank is placed into the primary-drive side bearing.

After dry-fitting the timing-side crankcase sealer is applied to the case halves and the timing-side case is mated to the primary-side case and the crankcase bolts are installed.

Don't forget the screws in the case mouth. They are installed with blue Loc-Tite.

The timing-side main bearing is oiled to prevent any damage from crank rotation.

Crankshaft end float is verified. The factory specifies a maximum of .017" but in reality anything below .025" is no cause for concern as the timing gears are straight-cut (instead of helical) and the primary drive is a chain, there really is nothing putting an axial load on the crankshaft.

Friday, October 25, 2013

Prepping the rockerboxes and rockers for assembly. The first two photos show a stock rocker compared to a rocker that has been contoured and polished. This is not done to lighten the rockers or for cosmetic reasons, but to deny cracks a place to begin. In stock form the rockers suffer no shortage of stress risers.

Here are the rockerboxes, cleaned and polished. I've lapped the cylinder head mating surfaces perfectly flat along with the inspection plug gasket surfaces. They were then set up in the mill so that the cylinder head bolt holes could be spot-faced to ensure that they are perfectly parallel to, and exactly the same height above, the head mating surface.

NOK manufactures all of the fork (and most other) seals for all of the
Japanese OEMs and for license-built OEM-Öhlins forks (which are
Japanese-made) so regardless of the OEM name on the wrapper the seal
originated in the same place. They make seals to the suspension makers'
design specification and therein lies the reason that the OEM-Öhlins
famously leak, the seal is of a different design to that of the Showa
and Kayaba spec seals. The Öhlins designed seal is meant to reduce drag
to a minimum but (and there is always a but) it is at the expense of
shorter seal life. The Showa/KYB designed seal puts a higher priority
on lifespan albeit with minimally more drag (none of us mortals would
ever know the difference) because most people who buy a Big Four brand
motorcycle would never put up with fork seals that started to leak
before the the first major service.

Trivia: Yamaha was majority owner of Öhlins corp from 1987 to 2007.

Your eyes aren't playing tricks, Ducati OEM Ohlins forks are only Titanium Nitride coated on the exposed portion of the tube.

In the video below I demonstrate the method that I use to determine the thickness of the pushrod tube seal to be used. The seals come two thicknesses, the white seals are .125 inches and the black seals are .100 inches.

Here are the crankcases cleaned and refinished with all bearings, bushings and seals installed.

Wednesday, October 23, 2013

Here we have a 2004 Multistrada 1000 that the owner brought in complaining of clunking in the chassis and idling issues. The owner proudly stated that this is a daily rider and that after the first time it got road salt on it washing it wasn't a big deal. The maintenance to this point had been performed by a combination of the owner and two separate dealerships.

Cause of the clunking sound. The drive pins MUST be engaged properly, these were not.

A compression check revealed 145 psi in the rear cylinder and 90 psi in the front cylinder. A wet compression test of the front cylinder failed to increase the reading and the valve clearances were found to be within specification. The exhaust valve stem did seem to have an excess of clearance in the guide. Upon removal of the head the worn exhaust guide was confirmed.

Tuesday, October 22, 2013

Next up is to remove the casting flash from inside the crankcase, timing chest and oil passages. The reason for doing this is twofold, first is to prevent any damage should a piece vibrate off and find its way to somewhere important and the second is to improve oil flow.

Monday, October 21, 2013

I thought that some of you might be interested in seeing what is
involved in the maintenance of your chosen flavor of motorcycle. Please note that this IS NOT A HOW-TO article/video. Several steps are not depicted and I will take no responsibility for your broken motorcycle if you decide that you can do this yourself. If you do not know which steps are not shown, then you should definitely NOT attempt this yourself.

Testastretta major service in photos and video:

Disassemble to gain access to the cams

Measure clearances

Disassemble to gain access to shims - The jaws of the forceps are
specially shaped and padded, also notice the complex tool holding the
opening rocker

Clean EVERYTHING

Everything is cleaned and ready for reassembly, the bolt threads are
lubed and the cam caps will have sealer applied at the appropriate
places

Measuring the actual shims

These are the half-rings that hold the works together

Shims reassembled

Verify corrected clearance

Install and tension cam belts

In the case of a 749/999, clean and oil the left and right air filter elements

There are many other checks that make up a major service such brake pad
thickness, bearings, fluids, TPS reset, maintenance reminder reset, etc.
but I just wanted to show the Ducati-specific items.
Older Desmoquattros are somewhat similar, Desmodues are not. At some point I will post the procedure for a 2-valve.

Now the rods must be balanced to each other by weight-matching the
small-ends (obviously the heavier of the two gets pared down to match
the lighter) and then weight-matching the entire rod by removing weight
from webs on the cap that are there for that purpose.

The tappet block oil returns are radiused and polished.

The tappet blocks installed in the cylinder block. The bores have been honed to a perfect fit with the new tappets.